| Full text | |
| Author(s): |
Metzker, Gustavo
[1]
;
de Aguiar, Inara
[1]
;
Souza, Maykon Lima
[1]
;
Cardoso, Daniel Rodrigues
[1]
;
Franco, Douglas Wagner
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, Chem Inst Sao Carlos, Sao Carlos, SP - Brazil
Total Affiliations: 1
|
| Document type: | Journal article |
| Source: | Canadian Journal of Chemistry; v. 92, n. 8, p. 788-793, AUG 2014. |
| Web of Science Citations: | 1 |
| Abstract | |
The reaction of the complexes trans-{[}Ru-II(NO+)(NH3)(4)L] and {[}Ru-II(NO+)HEDTA] with 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) and hydroxyl (OH center dot) radicals has been investigated at 25.0 +/- 0.1 degrees C using spectroscopic (UV-vis and electron paramagnetic resonance) and electrochemical techniques (differential pulse voltammetry and cyclic voltammetry). The redox potential of Ru-III/Ru-II for the ruthenium nitrosyl complexes was determined and is in the range of +2.2 V (L = HEDTA) to + 2.6 V (L = isn) versus the normal hydrogen electrode. The trans-{[}Ru-II(NO+)(NH3)(4)L](3+) and {[}Ru-II(NO+)HEDTA] complexes do not react with the DPPH center dot radical in aqueous solution at pH = 3.0. However, the corresponding aquo species, trans-{[}Ru-II(H2O)(NH3)(4)L](2+) and {[}Ru-II(H2O)HEDTA](+), respectively, react quantitatively, resulting in metal center oxidation. The trans-{[}Ru-II(NO+)(NH3)(4)L](3+) and {[}Ru-II(NO+)HEDTA] complexes react with OH center dot through a complicated pathway that leads to metal center oxidation followed by a series of secondary reactions. In addition to acting as NO donors, after their reduction, these ruthenium(II) nitrosyl complexes exhibit, through their generated aquo species, a radical scavenging ability, which is important for better understanding the already proven biological activity of these ruthenium nitrosyls in vivo. (AU) | |